I work somewhere that does a lot of acquisitions. We try to be nice and treat people fairly. If there are redundancies (we can centralize accounting, hr, etc) we try to be really frank and say "Look, we're a huge organization with lots of open reqs, do any interest you?"

There's always something to do around here and (as an example) if you're the super hot shit helpful person on migrating the seller's accounting system to the buyer's, even if your position is going away, we'd love to carve out a new position and keep you because you're rad.

We've bought ~20 companies since I've worked there and a lot of the people I work with now (as part of the parent / buyer org) are from the companies we've acquired. It's a good blend of talents. And when we're discussing terms for buying a new firm I think those people feel better seeing employees about that came from acquisitions.